Composite materials are more and more appealing for a great variety of uses in several industries such as the aeronautical industry, the naval industry, the automobile industry or the sports industry due to their great strength and strength-weight ratio.
The composite materials that are most used in said industries are those consisting of fibers or bundles of fibers embedded in a thermosetting or thermoplastic resin matrix, in the form of a preimpregnated material or “prepreg”.
A composite material part is formed by a plurality of preimpregnated material layers. Each preimpregnated material layer is formed by fibers or bundles of fibers which may be crosslinked with one another forming different styles of fabric or which can be oriented in a single direction forming one-way tapes. These fibers or bundles of fibers are impregnated with resins (either thermosetting or thermoplastic resins) which in many cases are partially polymerized.
Composite materials with an organic matrix and continuous fiber which are mainly based on epoxy resins and carbon fibers are currently massively used, mainly in the aerospace industry.
The level of use of this type of parts has increased in the aeronautical industry until the current situation, in which composite materials with an epoxy and carbon fiber matrix can be considered to be the most used option in a great variety of structural elements. This situation has forced and continues to force the development of manufacturing processes that can produce elements with the required quality repeatedly and with a suitable manufacturing cost.
The process for manufacturing composite material parts generally requires a compaction to obtain the desired fiber volume and to eliminate cavities and trapped air in the composite material and a curing process whereby the crosslinking of the polymer chains of the resin impregnating the fibers is achieved.
These parts have traditionally been manufactured by means of applying pressure and vacuum (as compaction means) and applying heat (as a means for achieving the crosslinking of the polymer chains), particularly in an autoclave inside which a controlled atmosphere is created.
An important aspect of the curing process of the composite material parts lies in making the resin flow, be diffused and degassed in a suitable manner to achieve complying with the quality requirements of the part and particularly to prevent cavities and other defects.
In this sense, U.S. Pat. No. 6,033,203 describes the application of a high frequency, low amplitude acoustic vibration during the curing process of a composite material part.
The industry constantly demands new tools and new methods allowing the decrease of both the time and energy necessary for manufacturing composite material parts.
The present invention is aimed at satisfying this demand